The disclosure relates to wavelength-division multiplexing and demultiplexing, and more particularly, to passive optical subassemblies with a signal pitch router to tune an optical signal path within an optical signal router.
Wavelength-division multiplexing (WDM) is a technology that multiplexes (e.g., adds) a number of distinct wavelengths of light onto a single optical fiber and demultiplexes (e.g., divides) a number of distinct wavelengths of light from a single optical fiber, thereby increasing information capacity and enabling bi-directional flow of signals. Multiple optical signals are multiplexed with different wavelengths of light combined by a multiplexer at a transmitter, directed to a single fiber for transmission of the signal, and split by a demultiplexer to designated channels at a receiver. By combining multiple channels of light into a single channel, WDM assemblies and associated devices can be used as components in an optical network, such as a passive optical network (PON).
Some optical assemblies are active optical subassemblies that require active individual tuning of the WDM filters, such as in configurations where the WDM filters are mounted separate from reflective surfaces (e.g., mirrors). In such a configuration, the WDM filters can be tuned by rotation or translation of the WDM filter relative to the common port, reflective surfaces, and/or channel ports. In other words, component placement and orientation is independent of one another.
However, in certain optical assemblies (e.g., passive optical sub-assemblies (POSA)), WDM filters may be mounted directly to a glass block, where the glass block operates as an optical signal router. By mounting the WDM filters directly to the glass block, tuning can be difficult and time consuming, if even possible. This is because the WDM filters are mounted to the glass block such that they must be placed and oriented collectively. In other words, placement and orientation of the glass block and WDM filters are dependent on one another. A lack of effective optical signal tuning for such configurations can lead to higher costs, higher fail rates, and/or less compact configurations.
No admission is made that any reference cited herein constitutes prior art. Applicant expressly reserves the right to challenge the accuracy and pertinency of any cited documents.